| Computer Code: |
DV |
Preferred Map Code: |
DV |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Basalt, hyaloclastite, basaltic tuffs and pillow breccias. |
| Definition of Lower Boundary: |
Overlies Upper Crafnant Volcanic Formation. Characterized by ill-sorted pyroclastic deposits with much included argillaceous debris. |
| Definition of Upper Boundary: |
Underlies the Nod Glas (= Cadnant Shales). |
| Thickness: |
400m |
| Geographical Limits: |
South and west of Dolgarrog. |
| Parent Unit: |
Snowdon Volcanic Group (SV)
|
| Previous Name(s): |
Part of Crafnant Volcanic Group [Obsolete Name and Code: Use DV]
(-2771)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Afon Porth-Llwyd. |
| Reference(s): |
| Howells, M F, Leveridge, B E, Evans, C D R and Nutt, M J C, 1981. Classical areas of British Geology. Dolgarrog. Description of 1:25 000 Sheet SH76. London: HMSO for Institute of Geological Sciences. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E106
|
